Abstarct: In this project, biocompatible bio-nanocomposites baxsed on the microcrystalline cellulose and β-cyclodextrin matrix together with the titanium dioxide nanoparticle filler were synthesized through click reaction. Titanium dioxide nanoparticles were synthesized in the anatase phase with a high purity and average particle size of 15-20 nm by sol-gel method. To prevent accumulation problems and to create a good distribution of titanium dioxide nanoparticles in organic solvents and substrates, their surfaces were modified with appropriate silane coupling agents. Modified nanoparticles were placed on the surface of modified microcrystalline cellulose and β-cyclodextrin matrices with a cupper catalyzed azide-alkyne cycloaddition (click reaction). The bio-nanocomposites structure were characterized by conventional detection methods such as FTIR, FESEM, XRD, EDX and etc. The Synthetic bio-nanocomposites were used as adsorbents for removing of heavy mextal ions such as zinc, cadmium, lead and mercury, as well as fluoride anion from aqueous solution by batch technique. By studying the isotherm (Langmuir, Freundlich, Temkin and Dubinin-Radushkevich models), kinetic (pseudo-first order, pseudo-second order, intraparticle diffusion and Elovich models) and thermodynamic of adsorption, the mechanism of ion adsorption by cellulose nanocomposite (Cell.Com) and cyclodextrin nanocomposite (CD.Com) indicates the chemical adsorption of single-laxyer ions on homogeneous adsorption sites. The results of ion adsorption showed that the Cell.Com and CD.COM are effective adsorbents for removing ions from aqueous solutions and their high adsorption capacity due to the synergistic effects of titanium dioxide, triazole rings and Cellulose/Cyclodextrin matrix. The Cell.Com and CD.COM adsorb ions during a short time due to the high surface area, porous structure, having a large number of functional groups as adsorbing sites, nitrogen heteroatoms of 1,2,3- triazole rings with chelating capability and the ability to form a host-guest complex. The antibacterial properties of Cell.Com and CD.COM were evaluated against gram positive (Staphylococcus aureus and Bacillus subtilis) and gram negative (Escherichia coli and Pseudomonas aeruginosa) bacteria using disk diffusion method in agar medium. The results showed that the Cell.Com and CD.COM have a wide range of antibacterial activities against both gram positive and negative bacteria due to the presence of titanium dioxide nanoparticles and triazole rings. The in-vitro cytotoxicity effect of synthetic bio-nanocomposites by MTT assay was investigated on normal fibroblast cells and cancer cells (HeLa, MCF-7 and Saos). The results indicate that bio-nanocomposites do not have meaningful cytotoxicity effect on normal fibroblast cells and have the ability to produce toxicity and destroy cancer cells. The triazole rings in the structure of the bionanocomposites play an important role in their anticancer properties.